气候变化领域集成服务门户(CCPortal): Mixing increases drought exposure through a faster growth in beech, but not in oak

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DOI	10.1016/j.foreco.2020.118593
	Mixing increases drought exposure through a faster growth in beech, but not in oak
	Jacobs K.; Bonal D.; Collet C.; Muys B.; Ponette Q.
发表日期	2021
ISSN	0378-1127
卷号	479
英文摘要	Promoting mixed forests is often seen as a management option to increase the resilience of forests to droughts. However, mixing can also improve tree growth, and if faster-growing trees use more water, they may be exposed to higher risks of drought. Across Belgium, we tested whether increased tree growth in mixed sessile oak/common beech stands results in increased drought exposure of these forests in severe dry summers. We sampled wood cores from 222 trees in mixed and corresponding pure stands at eight different sites and measured ring widths and stable carbon isotope composition (δ13C) in the wood formed during 2001 (wet summer as a reference year) and 2003 (severe dry summer). Pre-drought growth (PG), an index of tree growth in normal climatic conditions, was calculated as the mean ring width in the five years preceding the drought, and drought exposure was assessed as the difference in δ13C between the dry and the reference year. Growth of individual beech trees was faster in mixtures and both mixing and pre-drought tree growth were positively related to beech drought exposure. These two effects were not independent: the increased drought exposure in mixed stands was an effect of the faster growth. Analysis of δ13C values suggests that in reference conditions, beech trees in mixtures had a less conservative water use than trees in pure stands, but that they shifted to a functioning similar to that in pure stands under drought. By contrast, growth and drought exposure of oak trees did not differ between pure and mixed stands. Our results emphasize the different strategies of these two species regarding their response to mixing and drought. Beech maximizes its growth as a result of greater resource capture in mixed stands, but this increases the risk of suffering from severe droughts. Oak, on the other hand, exhibits lower variability in growth and in drought exposure across pure and mixed stands. We should stress that if mixing is used as a management strategy to mitigate the negative effects of climate change on temperate forests, forest managers should be aware that the performance benefits of mixed forests in non-drought years could in fact hinder the drought resistance of these forests in severe drought years. © 2020 Elsevier B.V.
英文关键词	Disturbance; Mixed forests; Species interactions; Stable carbon isotope composition; Stress
语种	英语
scopus关键词	Climate change; Drought; Mixing; Mixtures; Climatic conditions; Drought resistance; Management options; Management strategies; Performance benefits; Reference condition; Stable carbon isotope compositions; Temperate forests; Forestry; carbon isotope; climate change; drought; drought resistance; isotopic composition; risk assessment; water use; Drought; Exposure; Fagus Sylvatica; Forestry; Growth; Mixing; Mixtures; Trees; Belgium; Fagus
来源期刊	Forest Ecology and Management
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/154875
作者单位	Earth and Life Institute, Environmental Sciences, Université catholique de Louvain, Louvain-la-Neuve, Belgium; Université de Lorraine, AgroParisTech, INRA, UMR Silva, Nancy, 54000, France; Department of Earth and Environmental Sciences, Division of Forest, Nature and Landscape, KU Leuven, Leuven, Belgium
推荐引用方式 GB/T 7714	Jacobs K.,Bonal D.,Collet C.,et al. Mixing increases drought exposure through a faster growth in beech, but not in oak[J],2021,479.
APA	Jacobs K.,Bonal D.,Collet C.,Muys B.,&Ponette Q..(2021).Mixing increases drought exposure through a faster growth in beech, but not in oak.Forest Ecology and Management,479.
MLA	Jacobs K.,et al."Mixing increases drought exposure through a faster growth in beech, but not in oak".Forest Ecology and Management 479(2021).